The Rock Sequences and Mountainous Topography of the Northern Portion

The rock sequences and mountainous topography of the northern portion of the Appalachian Mountains__________ .

A) is made up of extinct composite cone volcanoes and massive intrusions formed above a Late Precambrian subduction zone
B) were barged across the Atlantic by homesick Scottish immigrants during the Highland Clearances
C) was made up mainly of Late Proterozoic, passive margin sedimentary strata that weren't deformed until the break up of Pangaea in the Late Carboniferous
D) consist of up to six different accretionary sequences, plastered onto the eastern margin of North America during the closing of the Iapetus Ocean over several stages of tectonic convergence between the Cambrian and Carboniferous